Process for the preparation of high molecular weight polyepoxides from polyepoxides and polyhydroxyl-containing compounds

ABSTRACT

The invention concerns a process for preparing epoxy resins of increased molecular weight by reacting a polyepoxide such as the diglycidyl ether of bisphenol-A with a polyhydroxyl-containing compound, such as bisphenol-A in the presence of an organometallic compound of tin, germanium, silicon and lead, such as trimethyltin chloride.

United States Patent 1191 1111 3,725,341 Rogers et al. 1 Apr. 3, 1973[54] PROCESS FOR THE PREPARATION OF [56] References Cited gggggggggggggg STATESPATENTS 3,398,211 8/1968 Ramos .....260/2 X POLYH'YDROXYLCONTAINING 3,150,l 16 9/1964 Masters .260/47 COMPOUNDS Inventors: MorrisGwynne Rogers, Sarnia, On-

tario, Canada; James Hwa-San Tsai, Kaohsiung, Taiwan The Dow ChemicalCompany, Midland, Mich.

Filed: June 23, 1971 Appl. N01; 156,101

Assignee:

US. Cl. ..260/47 EP, 260/18 EP, 260/47 EC,

Primary ExaminerWilliam l-l. Short Assistant Examiner-T. PertillaAttorney-Raymond B. Ledlie et a1.

[57] ABSTRACT The invention concerns a process for preparing epoxyresins of increased molecular weight by reacting a polyepoxide such asthe diglycidyl ether of bisphenol- A with a polyhydroxyl-containingcompound, such as bisphenol-A in the presence of an organometalliccompound of tin, germanium, silicon and lead, such as trimethyltinchloride.

9 Claims, No Drawings polyglycidyl ether, said preparation beingconducted in the presence of an organometal compound wherein the metalis silicon, germanium, tin or lead.

Polyglycidyl ether compounds have been prepared from polyglycidyl ethersand polyhydroxyl-containing compounds in the presence of such catalystsas tertiary amines, phosphonium compounds, quaternary ammoniumcompounds, alkali metal hydroxides and the like. Industry, however, isalways seeking alternate methods and processes for preparingpolyepoxides.

It has now been discovered that organometal compounds, wherein the metalis tin, silicon, germanium or lead, can be employed as the catalyst inthe reaction of a polyepoxide with a polyhydroxy compound.

The organometal compounds which are employed in the process of thepresent invention may be represented by the general formula wherein eachR is independently selected from the group consisting of alkyl groups offrom 1 to 10 carbon atoms, aryl groups, alkaryl groups, and aralkylgroups; X is sulfur, oxygen, hydroxide, alkoxide, alkanoate, or

a halogen having an atomic number from 9 to 53 inclusive; M is tin,silicon, germanium or lead; y is an integer from 1 to 2; 1 has a valueof from 1 to 2 and when z has a value of 2, X is sulfur or oxygen.

In the above formula, suitable alkoxides include those having from about1 to about 8 carbon atoms and preferably from about 1 to about 4 carbonatoms. Suitable lower alkanoates include those having from about 1 toabout 8 carbon atoms and preferably from about 1 to about 4 carbon atomsand includes such alkanoates as formates, acetates, propionates and thelike.

Suitable such organotin compounds include, for example, trimethylstannic chloride, trimethyl stannic bromide, trimethyl stannic iodide,triphenyl stannic chloride, triphenyl stannic bromide, triphenyl stanniciodide, trioctyl stannic chloride, trioctyl stannic bromide, trioctylstannic iodide, ethyl diphenyl stannic chloride, diethylphenyl stannicbromide, tributyl stannic iodide, tribenzyl stannic chloride, dimethylstannic dichloride, di(methylphenyl)stannic dibromide, tributyltinmethoxide, tributyltin acetate, tributyltin formate,bis(tri-N-butyl-tin)sulfide, bis(tri-N-butyltin )oxide, and the like.

Suitable organo silicon compounds include, for example, trimethylsiliconchloride, triethyl silicon chloride, triphenylsilicon chloride,diphenylsilicondichloride and the like.

Suitable organoleadcompounds include, for example, diphenylleaddichloride, triethyllead chloride and the like.

Suitable organogermanium compounds include, for

example, diphenylgermanium dichloride, tributylgermanium chloride andthe like.

The polyepoxides used in the process of the invention comprise thosecompounds possessing more than one 1,2-epoxide group. These polyepoxidesmay be saturated or unsaturated, aliphatic, cycloaliphatic, aromatic orheterocyclic and may be substituted if desired with non-interferingsubstituents, such as halogen atoms, phosphorus atoms, hydroxyl groups,ether radicals, and the like. They may also be monomeric or polymeric.

For clarity, many of the polyepoxides and particularly those of thepolymeric type are described in terms of epoxy equivalent values. Themeaning of this expression is described in U.S. Pat. No. 2,633,458. Thepolyepoxides used in the present process are those having an epoxyequivalency greater than 1.0.

Various examples of polyepoxides that may be used in the invention aregiven in U.S. Pat. No. 2,633,458 and it is to be understood that so muchof the disclosure of that patent relative to examples of polyepoxides isincorporated by reference into this specification.

Other examples include the glycidyl ethers of novolac resins, i.e.,phenol-aldehyde condensates.

Preferred resins of this type are those of the formula:

0 0 o (BL-EC o n 0 0 (1 (1 It R 1 wherein R is hydrogen or an alkylradical and n is an integer of l to about 10. Preparation ofthese'polyepoxides is illustrated in U.S. Pat. No. 2,216,099 and U.S.Pat. No. 2,658,885.

Other examples include the epoxidized esters of the polyethylenicallyunsaturated monocarboxylic acids, such as epoxidized linseed, soybean,perilla, oiticica, tung, walnut and dehydrated castor oil, methyllinoleate, butyl linoleate, ethyl 9,l.2-octadecandienoate, butyl 9,l2,l5-octadecatrienoate, butyl eleostearate, mono or diglycerides oftung oil, fatty acids, monoglycerides of soybean oil, sunflower,rapeseed, hempseed, sardine, cottonseed oil, and the like.

Another group of the epoxy-containing materials used in the process ofthe invention include the epoxidized esters of unsaturated 'monohydricalcohols and polycarboxylic acids, such as, for example, diglycidylphthalate, diglycidyl adipate, diglycidyl isophthalate,di(2,3-epoxybutyl)adipate di(2,3-epoxybutyl)oxalate, di-( 2 ,3-epoxyhexyl )succinate, di( 3 ,4-epoxybutyl)maleate, di(2,3epoxyoctyl)pimelate, di(2,3-epoxybutyl)phthalate,di(2,3-epoxyoctyl)tetrahydrophthalate, di(4,5-epoxydodecyl) maleate,di(2,3-epoxybutyl)terephthalate, di(2,3-epoxypentyl)thiodipropionate,di( 5,-epoxytetradecyl)diphenyldicarboxylate,di(3,4-epoxyheptyl)sulfonyldibutyrate, tri-(2,3-epoxybutyl) l,2,4-butanetricarboxylate, di(S ,6- epoxypentadecyl)tartarate,di(4,5-epoxytetradecyl)maleate, di(2,3-epoxybutyl)azelate,di(3,4-epoxybutyl)citrate,di-(5,6-epoxyoctyl)cyclohexane-l,3-dicarboxylate,di(4,5-epoxyoctadecyl)malonate.

Another group of the epoxy-containing materials include those epoxidizedesters of unsaturated alcohols and unsaturated carboxylic acids, such asglycidyl glycidate, 2,3-epoxybutyl 3,4-epoxypentanoate; 3,4- epoxyhexyl,3,4-epoxypentanate; 3,4-epoxycyclohexyl,3,4-epoxycycl0hexyl methylepoxycyclohexane carboxylate.

Still another group of the epoxy-containing materials include epoxidizedderivatives of polyethylenically unsaturated polycarboxylic acids, suchas, for example, dimethyl 8, 9, l2,l3-diepoxyeiconsanedioate; dibutyl7,8,1 l,lZ-diepoxyoctadecanedioate; dioctyl 10,1 1- diethyl-8,9,l 2, l3-diepoxyeicosanedioate; dihexyl 6,7,l0,ll-diepoxyhexadecanedioate;didecyl 9-epoxyethyl-l0,l l-epoxyoctadecanedioate; dibutyl 3-butyl- 3,4,5 ,6-dicpoxycyclohexane-l ,2-di-carboxylate; dicyclohexyl3,4,5,6-diepoxycyclohexane 1,2-dicarboxylate; dibenzyll,2,4,5-diepoxycyclohexane-l,2- dicarboxylate and diethyl 5,6,10,ll-diepoxyoctadecyl succinate.

Still another group comprises the epoxidized polyester obtained byreacting an unsaturated polyhydric and/or unsaturated polycarboxylicacid or anhydride groups, such as, for example, the polyester obtainedby reacting 8,9,l2,l 3-eicosanedienedioic acid with ethylene glycol, thepolyester obtained by reacting diethylene glycol with2-cyclohexene-l,4-dicarboxylic acid and the like, and mixtures thereof.

Still another group comprises the epoxidizcd polyethylenicallyunsaturated hydrocarbons, such as epoxidized2,2-bis(2-cyclohexenyl)propane, epoxidized vinyl cyclohexene andepoxidized dimer of cyclopentadiene.

The polyhydroxyl-containing compounds employed in the process of theinvention are phenolic compounds possessing at least 2 OH groupsattached to an aromatic nucleus. The phenols may be substituted with agreat variety of different types of substituents. Examples of thepolyhydroxyl-containing compounds include, resorcinol, pyrocatechol,hydroquinone, pyrogallol, hydroxyhydroquinone,2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(4-hydroxyphenyl) pentane, 2,2-bis(4-hydroxyphenyl)phloroglucinol, -2,2-bis (4- hydroxyphenyl)propane,2,2-bis(4-hydroxyphenyl)methane, 2-methoxyphenol, 2,4-dibutoxyphenol,2,5-dichlorphenol, 3-acetoxyphenol, 2,2-bis(3-allyl-4-hydroxyphenyl)propane, 2,2-bis(3-isobutyl-4-hydroxyphenyl)pentane, 1,1,2,2,-tetrakis(4-hydroxyphenyl)ethane, l,l,4-4-tetrakis(4-hydroxyphenyl)pentane and the like, and polymeric typepolyhydric phenols obtained by condensing monohydric or polyhydricphenols with formaldehyde, as well as phenols of the formulas n 15 to 25OlI Preferred polyhydroxyl-containing compounds to be used are thepolyhydric phenols containing from 2 to 6 OH groups and up to 30 carbonatoms. Coming under special consideration are the phenols of the formulaR R R. R

uo z---- on I l n It It I:

-SO,-R-SO,-- radicals wherein R is a bivalent hydrocarbon radical.

The amount of the epoxide and the polyhydroxylcontaining compound to beemployed in the process may vary over a wide range depending upon thetype of reactants and the type of product to be desired. In someinstances it may be desired to prepare compounds terminating in hydroxylgroups rather than epoxy groups. In these instances an excess of thepolyhydroxyl-containing compound is employed.

The amount of the organometal catalyst will vary over a wide range. Ingeneral, amount of catalyst will vary from about 0.001 percent to about10 percent by weight, and more preferably from about 0.05 percent toabout 5 percent by weight of the reactants.

The reaction may be conducted in the presence or absence of solvents ordiluents. In most cases, the reactants will be liquid and the reactionmay be easily effected without the addition of solvents or diluents.

l-lowever, in some cases, whether either or both reactants are solids orviscous liquids it may be desirable to add diluents to assist ineffecting the reaction. Examples of such materials include the inertliquids, such as inert hydrocarbons as xylene, toluene, cyclohexane andthe like.

When'solvents are employed in the reaction and the resulting product isto be used for coating purposes, the solvent may be retained in thereaction mixture. Otherwise, the solvent can be removed by any suitablemethod such as by distillation and the like.

The reaction may be conducted in an inert atmosphere such as nitrogen attemperatures from about 50 to about 300C, preferably from about l50200Cat pressures of from about 0.5 to about atinospheres, preferably fromabout 1 to about 2 atmospheres for from about 5 minutes to about 24hours, preferably from about 1 to about 10 hours.

The products obtained by the above process will be the desired phenolichydroxy ether compounds. Their physical characteristics will depend uponthe desired reactants and proportions. In general, the products willvary from liquids to solids, and in the case of the high molecularweight resins will vary from viscous liquids to hard solids. Theproducts will possess at least one alcoholic OH group formed by eachreaction of the epoxide and phenol OH group,.and can be further reactedthrough this group or groups. The polyfunctional reactants will alsogive products terminated in phenolic OH groups and/or epoxy groups, andthese will be available for further reaction.

A group of products which are particularly outstanding are those resinsand polymers obtained by the reaction of the polyepoxides and polyhydricphenols in controlled proportions. Those which use an excess of thepolyepoxide will be terminated in epoxy groups and can be used aspolyepoxides in known reactions of polyepoxides with curing agents andthe like. The new high molecular weight polyepoxides are particularlyuseful in preparing surface coatings, adhesives, laminates, filamentwindings, coatings forhighways and airfields, structural applications,formation of foams and the like. Those prepared from the halogenatedpolyhydric phenols as shown hereinafter are particularly useful as flameproofing resins for forming laminates. coatings and the like.

- 'lhe polyepoxides can be reacted with curing agents .to form hardinsoluble infusible products. The curing agents for the products includematerials which are preferably acidic or alkaline. Examples of suitablecuring agents include among others, the polybasic acids and theiranhydrides, such as, for example, the di, tri and higher carboxylicacids as oxalic acid, phthalic acid, terphthalic acid, succinic acid,alkyl and alkenylsubstituted succinic acids, tartaric acid, andparticularly the polymerized unsaturated acids, such as, for example,those containing at least 10 carbon atoms, and preferably more than 14carbon atoms, as for instance, dodecenedioic acid,l0,l2-eicosadienedioic acid, and anhydrides as phthalic anhydride,succinic anhydride, malic anhydride, nadic anhydride, pyromelliticanhydride and the like.

Other types of acids that are useful are those containing sulfur, N,phosphorous or halogens; chlorendic acid, benzene phosphonic, sulfonyldipropionic acid bis-(4-carboxyphenyl)amide.

Other preferred curing agents include the aminecontaining compounds,such as, for example, diethylene triamine, triethylene tetramine,dicyandiamide, melamine, pyridine, cyclohexylamine, benzyldimethylamine,benzylamine, diethylaniline,

triethanolamine, piperidine, tetramethylpiperamine,

N,N-dibutyl-l,3-propane diamine, N,N-diethyl-l,3- propane diamine,l,2-diamino-2-methyl-propane, 2,3- diamino-2-methylbutane,2,3-diamino-2-methylpen' tane, 2,4-diamino-2,6-dimethyloctane,dibutylamine, dioctylamine, dinonylamine, distearylamine, diallylamine,dicyclohexylamine, methylethylamine, ethylcyclohexylamine, pyrrolidine,2-methylpyrrolidiri'e, tetrahydropyridine, Z-methylpiperidine,2,6-dimethylpiperidine, diaminopyridine, tetramethylpentane,meta-phenylene diamine and the like, and soluble adducts of amines andpolyepoxides and their salts, such as described in U.S. Pat. No.2,651,589 and U.S. Pat. No. 2,640,037. acetone soluble reaction productsof polyamines and monoepoxides, the acetone soluble reaction products ofpolyamines with unsaturated nitriles, such as acrylonitrile, imidazolinecompounds as obtained by reaction of monocarboxylic acids'withpolyamines, sulfur and/or phosphorous-containing polyamines as obtainedby reacting a mercaptan or phosphine containing active hydrogen with anepoxide halideto form a halohydrin, dehydrochlorinating and thenreacting the resulting product with a polyamine, soluble reactionproduct of polyamines with acrylates and many other types of reactionproducts of the amines.

Still other curing agents that may be used include boron trifluoride andcomplexes of borontrifluoride with amines, ethers, phenols and the like,Friedel Crafts metal salts, such as aluminum chloride, zinc chloride,

and other salts, such aszinc fluoborate, magnesium perchlorate and zincfluosilicate; inorganic acids and partial esters as phosphoric acid andpartial esters thereof including n-butyl 'orothiophosphate, diethylorthophosphate and hexaethyltetraphosphate and the like.

Another type of curing agent to be employed in-- cludes the polyamidescontaining active amino and/or dimerizing and/or trimerizingethylenically unsaturated fatty acids containing up to 25 carbon atoms.These preferred polyamides have a viscosity between 10 and 750 poises at40C., and preferably 20 to 250 poises at Still other examples includethe 40C. Preferred polyamides also have amine values of 50 to 450.

Still another group of curing agents are those based on melaminereaction products containing methylol substituents.

The amount of curing agent may vary considerably depending upon theparticular agent employed. For the alkalies or phenoxides, 1 to 4percent is generally suitable. With phosphoric acid and esters thereof,good results are obtained with 1 to percent added. The tertiary aminecompounds are preferably used in amounts of about 1 to percent. Theacids, anhydrides, polyamides, polyamines, polymercaptans, etc. arepreferably used in at least 0.8 equivalent amounts, and preferably 0.8to 1.5 equivalent amounts. An equivalent amount refers to that amountneeded to give one active [-1 (or anhydride group) per epoxy group.

Solvents or diluents may also be added to make the composition morefluid or sprayable. Preferred solvents or diluents include those whichare volatile and escape from the polyepoxide composition before orduring cure such as esters as ethyl acetate, butyl acetate, Cellosolveacetate (ethylene glycol monoacetate), methyl Cellosolve acetate(acetate ethylene glycol monomethyl ether), etc., ether alcohols, suchas methyl, ethyl or butyl ether of ethylene glycol or diethylene glycol;chlorinated hydrocarbons such as trichloropropane, chloroform, etc. Tosave expense, these active solvents may be used in admixture witharomatic hydrocarbons such as benzene, toluene, xylene, etc. and/oralcohols such as ethyl, isopropyl or n-butyl alcohol. Solvents whichremain in the cured compositions may also be used, such as diethylphthalate, dibutyl phthalate and the like, as well as cyanosubstitutedhydrocarbons, such as acetonitrile, propionitrile adiponitrile,benzonitrile, and the like. It is also convenient to employ normallyliquid glycidyl compounds, glycidyl cyclopentyl ether, diglycidyl ether,glycidyl ether of glycerol and the like, and mixtures thereof.

Other materials may also be added to the composition as desired. Thisincludes other types of polyepoxides such as described in US. Pat. No.2,633,458. This also includes fillers, as sand, rocks, resin particles,graphite, asbestos, glass or metal oxide fibers, and the like,plasticizers, stabilizers, asphalts, tars, resins, insecticides,fungicides, anti-oxidants, pigments, stains and the like.

The temperature employed in the cure will vary depending chiefly on thetype of curing agent. The amino containing curing agents generally cureat or near room temperature and no heat need be applied. The acids,anhydrides, and melamine derivatives, on the other hand, generallyrequire heat, such as temperatures ranging from 150F. to about 400F.Preferred temperatures range from about 200F. to about 400F. and morepreferably from about 250F. to 350F.

The compositions containing the polyepoxides and curing agents may beused for a variety of important applications. They may be used, forexample, as adhesives for metal, wood, concrete, plaster and the like,and as surface coatings for various types of surfaces.

-The new compositions may also be used in the preparation of laminatesor resinous particles reinforced with fibrous textiles. They may also beused in the formation of castings and molding and for the encapsulationof electrical equipment.

In certain instances, such as when the resultant polyepoxide has anequivalent weight of above about 8000, the polyepoxides can be employedas solution coatings without the use of curing agents.

The degree of chain branching is determined by reacting the hydroxylgroups contained in the epoxy resin with trichloroacetyl isocyanatethereby forming a urethane group which produces a downfield shift of theassociated methine proton absorption in nuclear magnetic resonancespectra which when combined with considerations of model structures thenumber of chain branch points can be calculated.

The following examples are illustrative of the present invention, butare not to be construed as to limiting the scope thereof in any manner.In all instances nitrogen was passed through the reactor.

EXAMPLE 1 To a reaction vessel equipped with a means for stirring,nitrogen addition and temperature control was added 0.05 parts by weight(based on resin charge) (0.06 grams) of trimethyltin chloride dissolvedin 6.0 parts by weight (30 grams) of p-xylene and 27.44 parts by weight(137.2 grams) of the diglycidyl ether of p,p'- isopropylidine diphenolhaving an epoxide equivalent weight (EEW) of 192. After thoroughstirring, 12.56 parts by weight (62.8 grams) of p,p'-isopropylidinediphenol (bisphenol-A) was added. The reaction vessel was purged withnitrogen and the temperature was maintained between 185 and 190C for 5hours. After cooling 19.28 parts by weight (96.41 grams) of pxylene and34.71 parts by weight (173.6 grams) of methyl isobutyl ketone was addedresulting in a final product solution of 40 percent by weight on asolids basis. Analysis of the final product revealed the thus preparedpolyepoxide to have an epoxide content of 3.56 percent by weight on asolids basis. Based upon the ratio of the starting materials, thetheoretical percent epoxide of the final'product is 3.5 percent byweight.

EXAMPLE 2 In a manner similar to Example 1 above, a polyepoxide wasprepared from the following starting materials under the stated reactionconditions.

0.10 parts by weight (0.15 grams) based on resin charge of triphenyltinchloride dissolved in 8.88 parts by weight (35.29 grams) of p-xylene,

39.35 parts by weight (157.42 grams) of the diglycidyl ether ofbisphenol-A having an EEW of 192.

10.64 parts by weight (42.5 8 grams) of bisphenol-A.

The reaction was conducted between and C for 5 hours. After cooling, thefinal product was reduced to a 50 percent solids content by the additionof 7.92 parts by weight (31.7 grams) of p-xylene and 33.25 parts byweight (133 grams) of methyl isobutyl ketone. Analysis of the finalproduct revealed the resultant polyepoxide to have an epoxide content of10 percent by weight on a solids basis. The theoretical percent epoxidebased upon the ratio of the reactants is 9.5 percent by weight.

EXAMPLE 3 In a manner similar to Example 1 above, a polyepoxide wasprepared from the following starting materials under the stated reactionconditions.

0.0324 parts by weight (0.13 gram) of dibutyltindichloride dissolved in3.77 parts by weight (15.1 grams) of p-xylene,

33.48 parts by weight (134 grams) of the diglycidyl ether ofbis-phenol-A having an EEW of 192,

16.49 parts by weight (66 grams) of bisphenol-A.

The reaction was conducted between 185 and 190C for 4 2% hours. Aftercooling, the final product was reduced to a 50 percent solids content bythe addition of 46.2 parts by weight (184.9 grams) of methyl isobutylketone. Analysis of the final product revealed the resultant polyepoxideto have an epoxide content of 2.4 percent by weight on a solids basis.The theoretical percent epoxide based upon the ratio of the reactants is2.5 percent by weight.

EXAMPLE 4 In a manner similar to Example 1 above, a polyepoxide wasprepared from the following starting materials under the stated reactionconditions.

0.033 parts by weight (0.2 gram) of trimethyl-tin iodide dissolved in5.56 parts by weight (33.39 grams) of p-xylene,

33.32 parts by weight (200 grams) of the diglycidyl ether ofbis-phenol-A having an EEW of 192,

16.66 parts by weight (100 grams) of bisphenol-A.

The reaction was conducted between 187 and 195C for hours. Aftercooling, the final product was reduced to a 50 percent solids content bythe addition of 44.41 parts by weight (266.5 grams) of methyl isobutylketone. Analysis of the final product revealed the resultant polyepoxideto have an epoxide content of 2.46 percent by weighton a solids basis.The theoretical percent epoxide basedupon the ratio of the reactants is2.5 percent by weight.

EXAMPLE 5 In a manner similar to Example 1 above, a polyepox ide wasprepared from the following starting materials under the stated reactionconditions.

0.032 parts by weight (0.134 gram) of tributyltin methoxide dissolved in5.49 parts by weight (22 grams) of p-xylene,

33.48 parts by weight (134 grams) of the diglycidyl ether ofbis-phenol-A having an EEW of 192,

16.49 parts by weight (66 grams) of bisphenol-A.

The reaction was conducted between 185 and 190C for 6 7% hours. Aftercooling, the final product was reduced to a 50 percent solids content bythe addition of 44.48 parts by weight (178 grams) of methyl isobutylketone. Analysis of the final product revealed the resultant polyepoxideto have an epoxide content of 2.47 percent by weight on a solids basis.The theoretical percent epoxide based upon the ratio of the reactants is2.5 percent by weight.

EXAMPLE 6 In a manner similar to Example 1 above, a polyepoxide wasprepared from the following starting materials under the stated reactionconditions.

3.51 percent by weight on a solids basis. The theoretical percentepoxide based upon the ratio of the reactants is 3.5 percent by weight.

EXAMPLE 7 Further examples of catalysts for promoting the reactionbetween polyepoxides and hydroxyl-containing compounds are given inTable I.

The following charge was employed:

33.45 parts by weight (44.0 grams) of the diglycidyl ether ofbisphenol-A having an EEW of 192,

16.47 parts by weight (21.67 grams) of bisphenol-A,

0.067 parts by weight (0.088 gram) of catalyst,

8.82 parts by weight (1 1.6 grams) of p-xylene The reaction vessel waspurged thoroughly with nitrogen and the reaction mixture heated at to Cfor 5 hours. After cooling the mixture was reduced to a 50 percentsolids content by the addition of 41.18 parts by weight (54.16 grams) ofmethyl isobutyl ketone.

Catalyst activity is obviously, seen when the results are compared withthe reaction, carried out in the absence of catalyst.

TABLE I Epoxide content, percentage by weight on a solids basis after 5hours reaction Catalyst Epoxide Content None 7.60 Trir'nethyltin bromide4.36 Trimethyltin fluoride 4.36 Dimethyltin dichloride 4.75 Dimethyltindifluoride 5.54 Diethyltin dichloride 6.09 Butyltin trichloride 6.37Dibutyltin sulphide 4.07 Bis (tri-n-butyltin) sulphide 3.48 Tributyltinchloride 4.52 Tributyltin bromide 5.73 Tributyltin acetate 5.32 Bis(tri-n-butyltin) oxide 4.96 Dioctyltin dichloride 4.40 Trimethylsiliconchloride 4.52 Triethylsilicon chloride 3.72 Triphenylsilicon chloride3.78 Diphenylsilicon dichloride 4.91 Diphenylgermanium dichloride 3.86Trihutylgermanium chloride 4.07 Diphenyllead dichloride 6.68Triethyllead chloride 5.10

A further advantage of the new catalyst is that high molecular weightresins may be prepared that are either linear in molecular structure orhave any desired degree of chain branching. Generally the degree ofchain branching is dependent upon the type of catalyst selected. Thosecatalysts containing a tin-oxygen bond appear to control chain branchingnot only by type but also by their concentration. This latter effect maynot be restricted entirely to the Sn-O bond.

EXAMPLE 8 TABLE ll Catalyst Conc.

Product Reaction Chain We claim:

1. A process for preparing compositions higher in molecular weight thanthe starting components which process comprises reacting at temperaturesfrom about 50 to about 300C a polyepoxide having more than one 1,2-epoxygroups with an aromatic polyhydroxylcontaining compound in the presenceof, as a catalyst therefor, a catalytic amount of an organometalcompound represented by the general formula wherein each R isindependently selected from the group consisting of alkyl groups havingfrom about 1 to about 10 carbon atoms, aryl groups, alkaryl groups andaralkyl groups, X is an alkoxide, an alkanoate, sulfur, oxygen,hydroxide or a halogen having an atomic number from 9 to 53 inclusive, Mis tin, silicon,'germanium or lead, y is an integer from 1 to 2, 2 has avalue of l or 2 and when z is 2, X is oxygen or sulfur.

2. The process of claim 1 wherein the catalyst is an organotin compound.

3. The process of claim 2 wherein the polyepoxide is the diglycidylether of bisphenol A and the polyhydroxyl-containing compound isbisphenol A.

4. The process of claim 1 wherein the catalyst is an organosiliconcompound.

5. The process of claim 4 wherein the polyepoxide is the diglycidylether of bisphenol A and the polyhydroxyl-containing compound isbisphenol A.

6. The process of claim 1 wherein the catalyst is an organo leadcompound.

7. The process of claim 6 wherein the polyepoxide is the diglycidylether of bisphenol A and the polyhydroxyl-containing compound isbisphenol A.

8. The process of claim 1 wherein the catalyst is an organogermaniumcompound.

9. The process of claim 8 wherein the polyepoxide is the diglycidylether of bisphenol A and the polyhydroxyl-containing compound isbisphenol A.

2. The process of claim 1 wherein the catalyst is an organotin compound.
 3. The process of claim 2 wherein the polyepoxide is the diglycidyl ether of bisphenol A and the polyhydroxyl-containing compound is bisphenol A.
 4. The process of claim 1 wherein the catalyst is an organosilicon compound.
 5. The process of claim 4 wherein the polyepoxide is the diglycidyl ether of bisphenol A and the polyhydroxyl-containing compound is bisphenol A.
 6. The process of claim 1 wherein the catalyst is an organo lead compound.
 7. The process of claim 6 wherein the polyepoxide is the diglycidyl ether of bisphenol A and the polyhydroxyl-containing compound is bisphenol A.
 8. The process of claim 1 wherein the catalyst is an organogermanium compound.
 9. The process of claim 8 wherein the polyepoxide is the diglycidyl ether of bisphenol A and the polyhydroxyl-containing compound is bisphenol A. 